FIG. 10 is a partial cross-sectional view of prior art spring retainer 200, for example, for a vibration damper. A circumferential end of a spring (not shown), or an end-cap (not shown) for a spring engages portion 202 of retainer to circumferentially fix the spring. Ideally, the end cap and spring should remain in circumferential alignment, with the end cap substantially co-planar with a plane passing through an axis of rotation for the spring retainer. However, portion 202 is rounded. As a result, the spring and/or end-cap are able to slip and/or twist, resulting in damaging bending stresses for the spring and/or end cap. It is known to use a separate component, fixed to a spring retainer plate, to form a spring stop for the plate. However, the use of multiple components increases the cost, complexity, and fabricating time for the plate.